Cronulla's Ben Pomeroy on assault charge

Cronulla Sharks rugby league centre Ben Pomeroy has been charged with assault after a man's nose was broken at a Sydney rock concert last month.

Without naming the NRL player, police said a 23-year-old man had been charged with assault occasioning actual bodily harm.

"The charge relates to an assault at a rock concert at the Sydney Entertainment Centre on April 20," a police spokeswoman told AAP.

The 24-year-old victim told police he was punched in the face while in the crowd at a concert featuring American heavy rockers Korn.

The victim was treated by paramedics for facial injuries but was not taken to hospital, police said after the incident.

Four Sharks players - believed to be Pomeroy, Jacob Selmes, Dustin Cooper and Brett Kearney - were questioned, but released pending further inquiries.

Pomeroy's club refused to comment other than to confirm one of its players was involved in a police matter.

"The Sharks Rugby League Club wish to advise that as a matter involving one its players is now a police matter, no further comment will be made until the completion of the legal process," Sharks CEO Tony Zappia said in a statement.

Pomeroy is expected to play this Saturday when the Sharks take on the North Queensland Cowboys at Dairy Farmers Stadium in Townsville.